Researchers aim to cut risk of cornea transplant rejection

RESEARCHERS IN Galway are developing a way to modify donor corneas before they are transplanted, with a view to reducing the risk of rejection.

More than 100,000 corneal transplant procedures are carried out worldwide each year, according to researcher Dr Thomas Ritter, a senior lecturer in medicine at NUI Galway and a principal investigator at the Regenerative Medicine Institute.

“Normally corneal transplantation has a good prognosis of graft survival,” he said. “However, many patients who have had previous transplants or have problems with infections in the eye are at higher risk of rejecting the graft, and [may] have to be given systemic immunosuppression [medication], which has a lot of side effects.”

The team at Galway looked to modify donor cornea tissue before it is grafted in order to increase the eye’s ability to accept the transplant.

They inserted DNA into corneal cells to make them produce a factor called “programmed-death ligand-1”. This factor affects immune cells in the recipient’s eye and appears to create a more protective environment for the graft.

The technique has worked well in a pre-clinical study just published in the American Journal of Transplantation, according to Dr Ritter, who describes the results as “very exciting”.

The study, funded through Science Foundation Ireland, is continuing so they can better understand what programmed-death ligand-1 is doing to the recipient immune cells, he said.

While further work would be needed before use in the clinic, Dr Ritter said the cornea was a good tissue for the approach. “The advantage for the cornea is that it can be stored for a couple of weeks without loss of function. This gives us enough time to do this.”

The strategy could also potentially be of value for other transplant models, he added: “It could be applied, for example, to protect pancreatic islet cells transplanted for the treatment of type 1 diabetes.”

Gerry Fahy, a consultant ophthalmologist at University Hospital Galway, was also involved in this study. “Prevention of corneal transplant rejection is very important. This research describes a new exciting method of achieving that goal. I look forward to its translation into clinical use,”he said.